Science Saturday

I’ve been reading The Art of Subtext, a book about fiction and subtext by Charles Baxter. In a passage I read last night, Baxter writes about how much in our lives goes unheard, not deliberately (although there is that too), but out of a need to keep ourselves from being overwhelmed by the amount of noise surrounding us every day. We filter the messages we hear out of necessity. This made me think about a woman—a high-functioning autistic—I heard on NPR’s Fresh Air many years ago. She spoke about how rain sounded like a machine gun.

While it is still inconclusive that the climbing incidence of autism is due to anything other than a higher reporting rate and broadening definition for diagnosis, it is curious that in this age of sensory bombardment one of the leading psychiatric disorders among children is related to sensory overload.

Scientists believe that autism is at least partially caused by genetics, and most likely caused by a combination of genetics and the environment. I’m no scientist and anything that follows after this sentence is pure conjecture on my part—I like to theorize about these things if for no other reason than it is a kind of brain exercise.

I wonder about the evolution of the brain and how the reptilian aspects of our genealogy have come down in code that informs our instincts. Maybe there is some ancient gene that turned itself off thousands of years ago but over the last two centuries sparked up again as industry reared belching and clanging smokestacks, launched planes, trains, and automobiles, emitted cathode rays and spun mercury atoms into fluorescent lights.

A paper written by Temple Grandin, who is autistic, includes a section comparing animal behavior to that of an autistic child: “My reaction to being touched was like a wild horse flinching and pulling away. The reactions of an autistic child to touch and a wild horse may be similar. The process of taming a wild animal has many similarities to an autistic child’s reaction to touch. ”

Is this a sliver of our flinching, fleeing DNA that once protected us from predators? Our behavior is, in some part, informed by these spiraling codes. Carl Sagan, in The Dragons of Eden, postulated that sleep comes from our mammalian need to keep quiet while predators are on the prowl. Sleep is encoded in our DNA through the suprachiasmatic nuclei in our brain that controls circadian rhythms.

The intersection between environment and genetics makes my head spin. How many generations pass before a gene influenced by environment expresses itself? One? A thousand? Why does one gene switch on and another doesn’t? Are we just proteins and peptides and amino acids reacting to the food we eat and the air we breathe? Right now, is a sliver of a gene in my body overwhelmed by all these questions? Sigh. I think I’ll go back to reading about subtext.